Banjo yoke shafts

[Norm G]

My plane is a 41 BC12-65. The control yokes are the banjo type. The shafts are nickle plated. The shafts are worn and are in need of replating or replacement. The factory has nickel plated shafts but they don't come with the required welded flange and they are about a 1/2 shorter then mine. My questions are, where can I find the proper yoke shaft with the flange or should I get the originals replated. If I go the replating route do I need heat treating for embrittlement. Thanks in advance for the help.

Norm G

[Hank Jarrett]

Re: Banjo yoke shafts

Get a GOOD platting shop to do the replate. You will probably need to get a chem strip done first followed by flash plate (I think it's copper before a final Ni plate). IMMEDIATLY after plating (our spec used to be within 20 minutes) the shafts need to go into a 350 +- 25 degree bake for 23 hours. As I remember (this is ALL from memory when I was a plating engineer over 20 years ago) the 23 hours was actually a little long but we used it to keep the flow going (23 hours in the oven and an hour to switch embritlement relief rack). The required time for Hydrogen embritlement relief is based on a requirement for high strength steel but you will be safe using that spec for 4130. I heard an F-14 main landing gear piston crack sitting on a roll around wagon in our plating shop. Sounded like a 12 gauge shotgun going off.
A cheap shop will do the job for a lot less money but I don't even like to think what it would be like to have the wheel come off in my hand from a Hydrogen crack! Pay the extra and make sure they embritlement relief bake it. The cheap shops will argue with you that you don't need to relieve 4130. Is the guy telling you that going to fly your plane for the next decade or so?

[Ragwing nut]

Re: Banjo yoke shafts

Have your replated. United plating in Tulsa Ok does certified plating and baking.

Mike

[Norm G]

Re: Banjo yoke shafts

Thanks for the info on copper and nickel plating. After reviewing the requirements to re plate and the small amount of plating wear, my IA would rather not plate the parts and use them as is. Thanks again for your input.

Norm